Personally, I would not OC more than 2.
One reason is the possibility for multiple LEO calls for "Man with lots of guns running around". I have the right to open carry, and believe in "pushing the bounderies" some... but going around looking like "Duke Nukum" is likely to do more to harm the image a responsible OC does than to help it.
Both Pennsylvania state law and the License to Carry Firearms (LTCF) is silent on the subject of how many you can carry, either openly or concealed. Of course, if they're concealed you are required to possess an LTCF.